Method of cleaning and lubricating copper

ABSTRACT

A method of cleaning and lubricating hot copper with a lubricant cleaner which comprises by weight about 0.1% to about 2% of a lower aliphatic alcohol, about 0.06% to about 2% of alkali, about 0.1% to about 5% of an alkali metal soap, and water in an amount to bring the weight to 100%. The cleaner reduces the cupric oxide to copper and the cuprous oxide, solubilizing the cuprous oxide. It is preferred to immediately treat the oxide free copper surface with the soap and preferably also a lubricating oil to form a complex on the surface of the copper.

[ 1 Jan.7, 1975 METHOD OF CLEANING AND LUBRICATING COPPER [75] lnventor: Saul W. Klasky, Elkins Park, Pa.

[73] Assignee: G. Whitfield Richards Co.,

Philadelphia, Pa.

[22] Filed: Dec. 7, 1972 [21] Appl. No.: 313,132

[52] US. Cl .L 134/2, 134/15, 134/29, 148/132, 252/421, 252/156 [51] Int. Cl C23g 1/14 [58] Field of Search 134/2, 26, 29, 15; 252/156, 121, 549, 42.1; 148/132 [56] References Cited UNITED STATES PATENTS 2,198,719 4/1940 Coleman 148/132 2,992,997 7/1961 Arden et al.. 252/156 3,293,148 12/1966 Dell et al..... 252/156 3,433,683 3/1969 Osborn 148/132 3,447,965 6/1969 Teumac 134/2 3,481,877 12/1969 Moll 134/2 X 3,553,015 l/1971 Dohogne 134/2 3,684,720 8/1972 Richardson 2. 2/86 3,721,626 3/1973 Stanek ct a1 134/2 X Primary E.taminerS. Leon Bushore Assistant Examiner-M. Steven Alvo Attorney, Agent, or Firm-Smith, Harding, Earlcy & Follmer [57] ABSTRACT A method of cleaning and lubricating hot copper with a lubricant cleaner which comprises by weight about 01% to about 2% of a lower aliphatic alcohol, about 0.06% to about 2% of alkali, about 0.1% to about 5% of an alkali metal soap, and water in an amount to bring the weight to 100%. The cleaner reduces the eupric oxide to copper and the cuprous oxide, solubilizing the cuprous oxide, It is preferred to immediately treat the oxide free copper surface with the soap and preferably also a lubricating oil to form a complex on the surface ofthe copper.

8 Claims, N0 Drawings METHOD OF CLEANING AND LUBRICATING COPPER BACKGROUND OF THE INVENTION Copper wire is formed by cold drawing a copper rod of, for example, one-half inch in diameter, made by hot rolling cast copper bar. The'hot rolling operation re sults in the copper rod being covered with cuprous and cupric oxide which cause excessive die wear in the cold drawing operation and excessive breakage in the wire being formed.

Numerous procedures have been used to chemically remove the oxides prior to the' cold forming operation. The common practice is to pass the copper rod immediately after it is formed by hot rolling through a pickling tube through which sulfuric acid is circulated to remove the oxides. The thus treated rod is then rinsed has oxides on its surface when it is drawn into wire even if it is lubricated after descaling. Indeed, this inability to provide a copper rod without oxide on its surface for use in cold drawing is a basic defect in all prior art cleaning methods.

U.S. Pat. No. 3,620,853 teaches the removal of oxide scale by treating a copper rod with vapors of lower alkyl monohydroxy and polyhydroxy alcohols or lower alkyl ketones. This procedure fails to remove cuprous oxide and also fails to prevent the reformation of oxides on the copper rod surface.

This invention solves the prior art problem by not only removing all the oxides on a hot copper surface but also by preventing the reformation of said oxides. In addition, the invention is advantageous in that it provides a lubricant on the copper surface which increases die life and provides a good surface finish on the wire.

SUMMARY OF THE INVENTION An aqueous lubricant cleaner for hot copper comprises by weight about 0.1 to about 2 parts of a lower aliphatic alcohol, about 0.06 to about 2 parts of alkali, about 0.1 to about 5 parts of an alkali metal soap, and water in an amount to make an aqueous solution of these ingredients. Preferably about 0.5 to about 2 parts of lubricating oil is employed. The method comprises treating hot copper with the above described cleaner to reduce the cupric oxide, solubilizing the cuprous oxide, and immediately reacting the oxide free copper surface with the soap alone or with oil to form a copper complex on the surface of the copper.

DETAILED DESCRIPTION OF THE INVENTION The preferred composition of the lubricant cleaner is by weight as follows:

about 0.1% to about 2% of lower aliphatic alcohol about 0.06% to about 2% of alkali about 0.1% to about 5% of alkali metal soap water in an amount to bring the weight to 100% Preferably about 0.5% to about 2% of lubricating oil is also included.

The lower aliphatic alcohol will have the structure C,,H OH where n is an integer from one to four. Exemplary are methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, and butyl alcohol.

The alkali may be, for example, an inorganic alkali such as potassium hydroxide and sodium hydroxide or an organic alkali such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine', diisopropanolamine, or triisopropanolamine.

The alkali soap can be any anionic water soluble soap reactive with copper to form a copper soap complex, for example, an alkali metal salt of a higher fatty acid. Sodium or potassium sulfonates of a molecular weight of from 390 to 460 are also suitable. The sodium or potassium salts are preferred. Advantageously a sodium or potassium salt of oleic, stearic, palmitic acid, or mixtures thereof are used. The sodium or potassium salt of any mixture of the last mentioned fatty acids is also advantageous such as, for example, a sodium or potassium tallate.

It is preferred to include from about 0.5% to about 2% by weightof lubricating oil. The oil will be nonsaponifiable and liquid at room temperature. Petroleum oil and liquid higher fatty alcohols (from 8 to 18 carbon atoms) such as oleyl alcohol, decyl alcohol and lauryl alcohol.

The aqueous cleaner has a pH of from about 9 to about 12.5, preferably 9.6 to 10.5, and the alkali is em ployed in an amount to provide this pH.

While the above described percents by weight for the ingredients of the lubricant cleaner are the preferred ranges, the composition is operative at far higher concentrations of the essential ingredients and, for savings in shipping costs, may be shipped at much higher concentrations and, if desired, diluted by the purchaser prior to use. Thus, more broadly, the aqueous lubricant cleaner may comprise the following in parts by weight:

0.1 to 2 of lower aliphatic alcohol 0.06 to 2 to alkali 0.1 to 5 of an alkali metal soap It is preferred to also have 0.5 to 2 parts by weight of lubricating oil.

Only sufficient water to make an aqueous solution of the above ingredients need be used and a minimum is employed for shipment while dilution is desirable for actual use for cost saving. Thus generally the water will range from about 2 to about 300 parts by weight. The pH preferably is about 12 to 14.

I Brightening is also accomplished by the above preparations when using only the alcohol, alkali and water and leaving out any soap or oil.

The method of cleaning and lubricating hot copper in accordance with the invention involves treating the copper with the above described preparations advantageously in the preferred more dilute form with the copper at a temperature of from 800F to 1600F, preferably 1000F to l500F. The method involves reacting the cupric oxide on the surface of the hot copper with the lower aliphatic alcohol to reduce the cupric oxide to copper and cuprous oxide. The cuprous oxide is solubilized by the aqueous alkali solution. The thus provided oxide free copper surface is immediately treated with the alkali metal soap alone or with oil to form a complex on the surface of the copper which prevents the formation of copper oxides and acts as a lubricant.

In carrying out the method, the hot copper is immersed in the lubricant cleaner of the invention in, for

weight up to 100%.

the hot copper with the cleaner of the invention will 5 vary depending upon the temperature of the copper and the concentration of the ingredients in the lubricant cleaner, a treatment time of from 0.2 to 1 second is generally satisfactory. If a pickling tube is employed,

it is preferred to circulate the lubricant cleaner on a continuous basis through the tube at the rate of from about 50 to about 200 gallons per minute. In addition the lubricant cleaner can be used during the rolling of the copper bar to clean off oxides and lubricate the rolls by pumpng the lubricant cleaner on the rolls and 1 over the copper bar being reduced to the desired size. While the lubricant cleaner has a life of many months, it is necessary to continually replenish the ingredients since they are being used up continuously. The rates of replenishment are readily determined by periodic analysis. In addition, it is desirable to circulate the lubricant cleaner in and out of the vessel in which it is maintained for treating the hot copper cooling it down to a temperature under l50F before it re-enters the treating vessel to conserve the lubricant cleaner.

A suitable replenishment composition will have by weight to 80 parts of the alcohol and 0.5 to 5 parts of alkali in sufficient water to replenish the water used.

This composition may be added continuously or repeatedly at regular intervals of, for example, 1 hour. The remaining ingredients are replenished as needed generally less frequently.

The following examples giving percents by weight exceptwhere otherwise indicated will further clarify the lubricant and the method of cleaning hot copper of the invention:

The sodium oleate was dissolved in water and the methyl alcohol was then added. Finally, the sodium hydroxide was added and sufficient water was added to bring the total weight up to 100%.

EXAMPLE ll Ethyl Alcohol 1% Potassium Hydroxide l.5% Sodium Stearate 4.0% H 0 0.5. to bring total to l00% The sodium stearate was dissolved in water and the ethyl alcohol added. Finally, the potassium hydroxide was added and sufficient water added to bring the total EXAMPLE "I isopropyl Alcohol 2% Triethanolamine l% Potassium Stenrate 2% H,O 0.5. to bring total to The potassium stearate was dissolved in water and the isopropyl alcohol added. Finally, the triethanolamine was added and sufficient water added to bring the total weight up to EXAMPLE [V Propyl Alcohol 1% Sodium Hydroxide LSX Sodium Palmitute 271 H O 0.5. to bring total to IOU'X- The sodium palmitate was dissolved in water and the propyl alcohol added. The sodium hydroxide was then added and sufficient water was added to bring the total weight up to 100%.

EXAMPLE VI A lubricant cleaner prepared for shipment and subse- 0 quent dilution by the user had the following composition in parts by weight:

Methyl Alcohol L6 Sodium Hydroxide 0.6 Sodium Stearate 2.2 100 second petroleum oil .8 Water 4.9

The soap was dissolved in the water and the methyl alcohol added. Sodium hydroxide was then added.

EXAMPLE VII The lubricant cleaner of Example VI was diluted using water to give the following percents by weight:

Methyl Alcohol 0.16% Sodium Hydroxide 0.06 Sodium Stearate 0.22 100 second petroleum oil 0.08 Water q/s to [00% Methyl Alcohol 40% Sodium Hydroxide 4% Water 56% EXAMPLE Vlll N- propyl Alcohol 1% Sodium Hydroxide 1.5% Sodium Sulfonate (Molecular wt. 420) 2% Water Q/S to 100% The sodium sulfonate was dissolved in water and the n-propyl alcohol added. Then the sodium hydroxide and sufficient water was added to bring the total weight up to l00%.

EXAMPLE lX N-propyl Alcohol 1% Sodium Hydroxide 1.5% Water Q/S to l% It is to be understood that the foregoing examples are illustrative and are not intended to be limiting.

I claim: 1. The method of cleaning and lubricating copper to produce bright copper comprising:

treating copper coated with cupric oxide and cuprous oxide at a temperature of from about 800F to l600F with an aqueous liquid cleaner comprising by weight, about 0.1% to about 2% of a lower aliphatic alcohol having the structure C,,H OH where n is an integer from I to 4. about 0.06% to about 2% of an alkali selected from the group consisting of sodium hydroxide and potassium hydroxide, about 0.1% to about 5% of a water soluble alkali metal soap, and water in an amount to bring the weight to 100%, said cleaner having a pH of from about 9 to about 12.5, wherein substantially all of the cupric oxide and cuprous oxide are removed from the copper. 2. The method of claim 1 in which the cleaner contains from 0.5% to about 2% by weight of an unsaponi- 6 fiable oil.

3. The method of claim 2 in which the pH is from 9.6 to 10.5.

4. The method of claim 1 in which the alcohol is propanol.

5. The method of claim 1 in which the alcohol is isopropanol.

6. The method of producing clean bright copper from copper coated with cupric oxide and cuprous oxide by treating the coated copper with a lubricant cleaner comprising:

reducing the cupric oxide to copper and cuprous oxide by treating the coated copper at a temperature in therange of from about 800F to about 1600F with a lower aliphatic alcohol having the structure C,,H OH, where n is an integer from 1 to 4, in the lubricant cleaner, and

solubilizing the cuprous oxide with an aqueous solution of alkali in the lubricant cleaner, the alkali being selected from the group consisting of sodium hydroxide and potassium hydroxide,

wherein substantially all of the cupric oxide and cuprous oxide are removed from the copper.

7. The method of claim 6 in which the oxide free copper is immediately reacted with a water soluble alkali metal soap in the lubricant cleaner to form a coppersoap complex.

8. The method of claim 7 in which the oxide free surface is also treated with a non-saponifiable lubricating 

1. THE METHOD OF CLEANING AND LUBRICATING COPPER TO PRODUCE BRIGHT COPPER COMPRISING: TREATING COPPER COATED WITH CUPRIC OXIDE AND CUPROUS OXIDE AT A TEMPERATURE OF FROM ABOUT 800*F TO 1600*F WITH AN AQUEOUS LIQUID CLEANER COMPRISING WEIGHT, ABOUT 0.1% TO ABOUT 2% OF A LOWER ALIPHATIC ALCOHOL HAVING THE STRUCTURE CNH2N+1OH WHERE N IS 1 TO 4, ABOUT 0.06% TO ABOUT 2% OF AN ALKALI SELECTED FROM THE GROUP CONSISTING OF SODIUM HYDROXIDE AND POTASSIUM HYDROXIDE, ABOUT 0.1% TO ABOUT 5% OF WATER SOLUBLE ALKALI METAL SOAP, AND WATER IN AN AMOUNT TO BRING THE WEITHT TO 100%, SAID CLEANER HAVING A PH OF FROM ABOUT 9 TO ABOUT 12.5, WHEREIN SUBSTANTIALLY ALL OF THE CUPRIC OXIDE AND CUPROUS OXIDE ARE REMOVED FROM THE COPPER.
 2. The method of claim 1 in which the cleaner contains from 0.5% to about 2% by weight of an unsaponifiable oil.
 3. The method of claim 2 in which the pH is from 9.6 to 10.5.
 4. The method of claim 1 in which the alcohol is propanol.
 5. The method of claim 1 in which the alcohol is isopropanol.
 6. The method of producing clean bright copper from copper coated with cupric oxide and cuprous oxide by treating the coated copper with a lubricant cleaner comprising: reducing the cupric oxide to copper and cuprous oxide by treating the coated copper at a temperature in the range of from about 800*F to about 1600*F with a lower aliphatic alcohol having the structure CnH2n 1OH, where n is an integer from 1 to 4, in the lubricant cleaner, and solubilizing the cuprous oxide with an aqueous solution of alkali in the lubricant cleaner, the alkali being selected from the group consisting of sodium hydroxide and potassium hydroxide, wherein substantially all of the cupric oxide and cuprous oxide are removed from the copper.
 7. The method of claim 6 in which the oxide free copper is immediately reacted with a water soluble alkali metal soap in the lubricant cleaner to form a copper-soap complex.
 8. The method of claim 7 in which the oxide free surface is also treated with a non-saponifiable lubricating oil. 